Lamb Survival

Improving lamb survival is a critical part of improving the profitability of sheep breeding enterprises. A publication from the EverGraze series highlights some important strategies for maximising lamb survival.

The full article can be found at: http://evergraze.com.au/fact-sheets.htm

Following are the key messages:

• A 10% increase in lamb survival can increase the gross margin of a prime lamb operation by 10% or $5 - $6 per ewe.

• 70% of lamb mortality occurs in the first 48 hours after lambing.

• Lamb birth weight is directly linked to mortality through starvation, mis-mothering and exposure.

• Twin lambs are more susceptible than singles.

• Lamb survival is maximised when ewes are in condition score 4 at the time of lambing.

In the short term, ewe nutrition prior to lambing is the most significant factor affecting lamb birth weight and hence lamb mortality.

Ewe nutrition during early pregnancy (prior to day 90) influences lamb birth weight through an effect on placental development. However, nutrition in the last 50 days of gestation has the greatest effect on birth weight, as this is the period when the foetus is growing fastest.

Colostrum production occurs in the last week of pregnancy, with ewe nutrition greatly impacting on the quantity and quality of colostrum. Adequate nutrition during lambing also removes the temptation for ewes to move away from the birth site, a common cause of mismothering.

Evergraze guidelines suggest that ewes should be on a rising plane of nutrition as they approach lambing. The minimum feed on offer targets for lambing ewes is 1,200 kg DM/ha for singles and 1,800 kg DM/ha for twins.

More details on lamb survival plus other livestock and pasture management issues can be found on the EverGraze website: http://evergraze.com.au.